Latch tripping mechanism



H. W. SANFORD LATCH TRI'PPING MECHANISM Sgpt. 12, 1950 3 Sheets-Sheet 1 Filed Dec. 51, i948 H. W. SANFORD LATCH TRIPPING MECHANISM Sept. 12, 1950 5 Sheets-Sheet 2 Filed Dec.

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M JQMJ M t Sept. 12, 1950 H. w. SANFORD LATCH TRIPPING MECHANISM 3 Sheets-Sheet 3 Filed Dec. 31, 1948 Patented Sept. 12, 1950 UNITED STATES PATENT OFFICE.

LATCH TRIPPING MECHANISM HnghW. Sanford,v Knoxville, Tenn, assignor to The Sanford Investment Company, Wilmingtton, DeL, a, corporation of Delaware Application December 31, 1948; Serial No. 68,677

11 Claims. 1 V

This invention relates to improvements in.

Latch Tripping Mechanisms, particularly for mine cars and other conveying devices having.

drop bottom doors for the discharge of the lading therefrom.

This invention is an improvement on the latch tripping mechanisms set forth in my prior applieations, Serial No. 432,341, filed February 25, 1942, now Patent No. 2,399,708, granted May '5,

1946; Serial No. 571,170, filed January 3 I945;

a released position, thereby unlatching or releasing the door for dropping movement. The contact and tripping members utilized for such prior devices were disposed in side-by-side: relation substantially in the same upright transverse plane, whereby the contact member connected with the tripping member would ride along the under surface of the car and control the movement of the tripping member in response to the contour of the under-surface of the car.

An object of this invention is to. improve the construction of the. tripping mechanism to provide for the location of the contact member and tripping member, or respective faces thereon, in the same upright longitudinal plane so these:

faces will act on the same portions of the under-- surface of the car or conveying device, and the contact member will deflect the tripping member away from such under-surface in vertical alignment therewith against engagement by the tripping member, such as would interfere with the passage of the conveyance thereover.

Where the contact and tripping members are located in side-by-side relation as in my prior applications, occasionally some part of the car may engage the tripping member in its raised" position which would not extend across the car far enough to engage the contact. member, which thereby may interfere with the operation of the object may be accomplished according to oneembodiment of the invention by providing an engaging or contact face on a single tripping arm in the same upright longitudinal plane in such position as to ride: along the under-surface of the car or conveyance and be pressed upward in position for the tripping face to engage and release the latch hook from supporting engagement with the bottom door.

A further object of the invention is to simplify and improve the construction of tripping mechanism by locating the engaging and contact faces conveying device or dislocate parts of the-tripping on a single tripping arm, so as not to require separate laterally spaced faces or arms in sideby-side relationship, as provided heretofore.

These tripping and contact faces may be formed one behind another in the same upright longitudinalplane and in such position that the con-' tact face will engage the portion of. the car structure, such as the end sill, to insure of carrying down the tripping face so as not to become entangled therewith. Furthermore, it is preferable that the supporting member for the contact and engaging faces be located so as to swing tact therewith.

This embodiment of the inventionis illustrated in the accompanying drawings in which:

Fig. 1 is a side elevation of a mine car and" latch tripping mechanism;

Fig. 2- is a cross section through the tripping mechanism, showing portions of the mine car v for related thereto, other portions being omitted simplicity of illustration;-

Fig 3' is a longitudinal sectional view there'- through showing the latch in engaged position;

Fig.4 is a similar view showing the latch re-" elevation showing a modified form of tripping member; and

Fig. 7' is a top plan view of a tripping member" detached and showing a further modified com struction.-

This invention is shown as applied to a mine" car of the general type set forth in my prior patent; No. 2,001,471, granted May 14, 1935,

adapted for conveying coal or other loose ladi-ng from a receiving point to a tipple or other point of discharge. The mine car is shown to be of the 4-wheel type, having three drop bottom doors interconnected for release in one-two-three order. This application of the invention is used, however, merely for purpose of illustration, and it is evident that the subject-matter of this invention may be applied to other types of cars, vehicles, and drop;;bottom conveyors in general,

wherever it may be desirable to release bottomdoors for dropping, in which the principle of this invention may be applicable.

The general structure of the car illustrated comprises a car body formed of side and end walls I and 2, rigidly secured together, the side Walls I rising from a pair of .oppositely disposed side sills 3 (Figs. 1 and 2), connected together at the ends of the car by means of combined.

The car is shown of the character providedwith three drop bottom doors adapted for discharge in one-two-three order from front to rear of. the car. These doors are designated respectively by the numerals 8,9 and I5. The forward door 8 is pivotally supported at its forward edge on a hinge rod, while each of the middle and rearward doors 9 and I is slidably and pivotally mounted on a hinge rod I2 extending betweentheframe structures atopposite sides of the drop bottom opening. Any other suitable door construction or arrangement maybe used as desired.

The extreme forward edge of each of said doors 9 and), when in closed or latched position, projectslaterally from the hinge rod I2, and is adapted to support the freeedge of the next for- Ward door. Then upon release of th rearward door, it may drop sufiiciently to drag and move bodily rearward, thereby releasing the free edge of the middle door which will likewise drop and release the free edge of the forward door. This occurs usually just befor the car reaches the tipple .or bin, and permits dropping of the forward door in the bin for discharge of thelading thereon, as soon as room enough is provided in the bin therebeneath. The other doors drop in succession during the continued forward movement of the car over the bin or tipple in onetwo-three order from front to rear of the car.

After dumping in passing over the bin or tipple, th e doors are adapted to be closed by the usual door-closing rails located in th track. The doorsmay have indentation I3 in the under faces thereof to ride on the door-closing rails,

which indentations would extend transversely of the doors throughout substantial portions of the width thereof. The doors are thus moved successively about their hinge rods to their closed positions, and the middle and rearward doors are pushed; forward intowedging relation with the next forward door, adapted to be latched in closed position.

,The foregoing car structure, to which this ,in-

vention is shown applied as hereinafter described, is set forth more in detail inmyprior patents,

No. 2,001,471, May 14,. 1935, and ,No. 2,036,644,,

' adjacent bumper plate of the car.

4 April '7, 1936, to which reference is made for a more complete illustration of the structure thereof.

As shown in Figs. 1 and 3 to 5, provision is made for latching the free edge of the rearward door II) in closed position, thereby holding the several doors closed, to retain the lading in the car until'thelatching means is released for dumping.- For this purpose, -I"have provided on the free edge of the rearward door If], one or more supporting trunnions I4, one for each latch of said door. I prefer to use a pair of latches, each designated generally by the numeral I5 and spaced apart as indicated in Fig. 2, symmetrically with respect to the longitudinal center of the car. The latches I5 are pivotally mounted on a cross shaft I'I supported by brackets l8 secured to the Each of the'latches I5 is preferably so constructed, or spring-pressed, as to be disposed normally in its door supporting position, or to return thereto automatically when disengaged for release of the lading.

Each ofthe latches I5 is provided with a seat I9 (Fig. 3) at the forward face thereof in position to receive the end of the adjacent trunnion I4 attached to the free edge of th rearward door "1.. As shown in Fig. 3, the seat I9 is located on theopposite side of the vertical plane passing through'the pivot axis of the latch I5 from the door II], so that the Weight of the door and the lading; thereon tends to maintain the latched relation without any tendency for this weight torpush the latch to one side.

-Each' of the latches I5 is provided, preferably, with av lateral pin 20 attached thereto and projecting through a slot 2i in the adjacent portion of the end-sill plate 5 (Figs. 3 and 4).

.Theforegoing structure corresponds generally with that set forth in my prior application for Door Latch Mechanisms, Serial No, 432,341, filed February 25, 1942, now Patent No. 2,399,708, granted May 7, 1946.

- As shown in Figs. 3 and 4, the latches I5 are interposed between the free edge of the rear- Ward .door It] and the adjacent end-sill structure 4, underneath a deflector plate 23 secured to gthe'adjacentend wall 2. The latches I5 are so constructed and arranged that they are disposed whollyabove the lower edges of the end- Each latch I5 is so mounted in protected po- I sition between the doorv III and the bumper 4 that a tripping, space is provided between said door and. the latch I5 in latched position for entry of a tripping arm therebetween,

-,T.o accommodate the tripping mechanism hereinafter, described, each latch hook has its forward face, beneath the seat I 9, provided with a notch 25 therein, having a lower engaging face 26 ;whichslopes downwardly and forwardly relativeto the length of the car. This face 26 is adapted to be engaged by the tripping arm as hereinafter described, and as shown in Figs. 3 and 4, to release the latch hook from supporting engagement with the door.

filfhe tripping mechanism for the latches I5 is adapted to be mounted in the trackway between awards:

the opposite r'ails R- at a point. adjacent thebin or other place of dumping. Since the, latches l5 are laterally displaced symmetrically on opposite sides of the longitudinalvertical plane through the center of the car, a tripping device may be mounted preferably on a base 2?, shown in the form of a supporting plate securely mounted in suitable position inthe trackway, preferably by being secured, as shown, upon the base flanges of the rails R. Secured to the under side of the supporting plate 21 are bearing boxes 28 and 28', the bearing boxes 23 being disposed adjacent opposite edges of the plate 21, while the bearing box it is in axial alignment therewith midway of the width of the plate.

Shafts til extend transversely between the bearing box 28' and each of the bearing boxes 28, and are arranged in axial alignment with each other on respective opposite sides of the center of the tripping device. The shafts 30 are independent of each other and capable of separate operation to provide for the independent unlatching of the respective latches, although one shaft may be used for the tripping elements of both latches, if they are to. be unlatched simu1- taneously. In that event, only twobearing boxes will be required.

In the form shown, each of the shafts 36 has fixed thereon, as by welding, an upwardly extending tripping arm 3! which is inclined forwardly of the direction of movement of the. car as illustrated in Fig. 3. The arm 3| supports on its upper forward end thereof a contact member 32, the upper face of which is somewhat wedge-shaped and is adapted to be deflected under the lower face of the car during movement of the latter over the tripping mechanism, so as to deflect this contact member beneath the car. The contact member 32 is shown as integral with the arm 3 l, although it may be a separate member secured thereto.

The forward upper end of the tripping arm 3! also carries an offset hook or bar 34 which has a wedge shaped upper edge portion 35 in position to enter the notch 25 and engage the face 26 when the contact member 32 is substantially inv its uppermost position, as shown in Figs. 3

and 4-. The offset hook 3d acts as a tripping member and is disposed at the upper end of the arm 3| in the same upright longitudinal plane as the contact member 32, which contact member should be at least as high as the tripping member, or slightly higher, as shown.

The contact arm 3! is arranged to extend upwardly through the dumping plate 21 which is slotted. attfi, to accommodate this arm, as shown in Fig. 2, for freedom of upward and lowering movement thereof. The arm 3 is mounted on each shaft 3% with the tripping member 34 in position to engage and actuate the latch, while the contact member 32 is guided under the bottom contour of the car passing thereover. The contact face of the member 32 has a sufficient slope relative to the contact edge of the latch l5, and is so yieldably mounted, that said contact member 32 will not disengage the latch but will be deflected therefrom as described. However,

position shown inFi-g. 3. for" release of the latch 15 by the tripping portion, 35. I Welded or otherwise secured to) one side of the tripping arm 3|. is an abutment 39 in posi- 5 tion to engage the lower end of a. limit screw 4.0..

This screw All! is threaded through the dumping plate. 2i and through a threaded bar 4| fixed to the under side thereof, as shown in Fig. 3. This limit screw it may be adjusted up. and down with respect to the dumping plate 2'! and locked in its'adjusted position by a jambnut 42. When. properly adjusted, the limit screw 40 will :be in,

position to engage the abutment 3.9, so as to limit the upward swinging movement of the tripping arm 3! and thereby limit the upward movement of the contact member 32 and tripping member 34.

These: parts are held yieldably in elevatedposi-- tions by a coiled spring 43, which is connected atone end with an eye-bolt 44, as shownin Fig. 1, attached to a bracket '25, suspended from the dumping plate 21 The eye-bolt M. is adjustably connected atdd with the bracket t5, as by nuts threaded on the end of the eye-bolt, for varying the tension of the spring. The opposite end of the spring it. is connected to the lower end of the lever arni H, extending downwardly from each of the shafts 3E]; The tension of the spring t3. should be suflicient to hold each set of tripping mechanism in its elevated position normally until depressed by the passage of the car or other conveyance thereover, whereby the contact and tripping elements will be deflected under the bottom structure of the car or conveyance to operative positions as shown in Figs. 3 and 4.

This action will position the tripping edge 35, so as to cause engagement thereof with the downwardly and forwardly inclined fac 26 of the latch hook as the car passes over the tripping mechanism, and thereby will move the latch hook from its latched position, as shown in 3, to its unlatched position as shown in Fig. 4. This will release the trunnion M from the latch seat I9,

As the tripping edge 35 engages the face 26 of thelatch hook during the forward movement of the car over the tripping mechanism, and swings the latch hook to its released position, the angle of the face 26 changes with respect to the angle of the tripping arm 33, while said arm 33 remains substantially in the same position. During this movement, the downward inclination of the face 26 forwardly of the car will tend to push upward on the tripping edge 35 to insure the maintenance of engagement of this tripping edge with the face 25 throughout the time that the latch it is being moved to its released position. Thus there is no tendency forthe tripping edge to slip off the latch hook, but any tendency of relative movement between these edges is upward rather than downward, to increase the holding action of the tripping member on the latch until the latter is moved to its released position. Through the entire movement of the The release of the rearward hook, the co-eflicient of friction between the tripping edge and the latch is sufficient to prevent the latch from slipping on" the hook against the action of the spring 43 which is tending to hold the tripping edge 35 as high as it is permitted to go by the adjustable limit screw 40. Thus the latch is effectively released without any danger that the tripping member will be deflected without releasing the latch.

I have shown in Fig. 5, a diagrammatic view illustrating different positions of the tripping arm 3!, contact element 32 and tripping face 35, with respect to different parts of cars coupled in interconnected relation, .to illustrate how the tripping member will follow the contour of the under surface of the car in a wiping action therewith. The contact element 32 being at the same or slightly higher elevation than the tripping face 35 when they pass under the bumper structure 4, and in the same upright longitudinal plane, will locate the tripping face, so as not to catch in any part of the car which would destroy the tripping mechanism or cause damage thereto. Thus the contact element 32 will depress the tripping face 35 before the latter engages the forward face of the end sill and will insure that the tripping face will always clear obstructions on the under surface of the car.

This action is facilitated by the location of the pivot point 30 for the arm 3|, in a direction reanwardly of the contact face 32, and tripping face 35, whereby the arm will drop in a direction away from the portion of the car engaged by the contact face, swinging downwardly in a direction toward the front of the car in its forward movement along the track, rather than rearwardly. This insures that the engagement of the contact face on-the element 32 with the bottom of the end sill structure does not have a destructive effect on the tripping arm but pushes it down so that this arm will pass underneath the end sill structure without becoming entangled therein. The location of the pivot point 311 forward of the contact member 32 would not be practical for a mine car or other conveyance unless there is room enough for a considerable travel during the unlatohing period.

I have also shown in Fig. 6, a modified form of tripping arm 3la, wherein the head portion 34a thereof which carries the tripping face 35, is so enlarged in its longitudinal dimensions as to engage the upwardly inclined rear edge of the door II), when the face 35 is in its tripping position or in position for contact with the latch hook 15. This tends to support the door so that its weight bearing on the upper end of the contact arm will also deflect the arm and facilitate itsdropping movement as soon as the latch is released from the free edge of the door.

A further modification is shown in Fig. 7, in which the tripping arm 3|?) has the head portion 34b of the same width as the arm. This provides the contact element 32b, and the tripping element 35b, of the same width as the body of the tripping arm. This enables the entire structure to be cast in one piece and to be of uniform width, if desired.

While I have shown two separate tripping devices for the respective latches spaced on opposite sides of the longitudinal center of the car and prefer to use such separate devices, a single tripping device may be used if the latches are fixed to the cross shaft I1. Generally, however, it is preferred to use separate tripping devices for the respective latches,-

When the conditions of operation are such that the rear end of the car may be caused to slue sideways, so that it may be possible for one tripping device to release its latch before the other has unlatched its latch, the respective latches should be mounted independently for relative movement on the cross shaft l7, rather than fixed thereon. When this is so provided, each latch will be released independently and regardless of the way the car is slued, and regardless also of any variation in the length of the respective tripping arms or in the set-up of the mechanism.

It will be appreciated also that any suitable form of latch may be used in place of the form' illustrated, such for instance,- as that set forth in my prior applications, Serial No. 432,341, and

Serial No. 571,170, mentioned above, and the tripping face or member may be modified to conform thereto, without being limited to the form shown. should be in the same upright longitudinal plane and may be co-extensive with each other in such position as to ride along the under-surface of the conveyance and to cause a tripping engagement with the latch hook or latch release member.

While the invention has been illustrated and described in certain embodiments, it is appreciated that other variations and changes may be made therein without departing from the invention, except as specified in the claims.

I claim:

1. In conveying mechanism, the combination with a trackway, a dumping conveyance movable along the trackway and including a lading body with a drop bottom door, and latch means for holding the door closed and movable to release the door for opening, of tripping mechanism mounted at the trackway and including latch release means in position to engage the latch means during movement of the conveyance over the tripping mechanism to release the door for opening, and contact means connected with the latch release means, and said contact means being in position for engagement by the under-surface of the conveyance during movement thereof over the tripping mechanism for controlling the releasing position of the latch release means, said contact means being substantially in the same longitudinal upright plane as the latch release means to engage successively the same longitudinal portions of the conveyance.

2. In conveying mechanism, the combination with a trackway, a dumping conveyance movable along the trackway and including a lading body with a drop bottom door, and latch means for holding the door closed and movable to release the door for opening, said latch means including engaging means for operating the latch means, of tripping mechanism mounted at the trackway and including latch release means in position to engage said engaging means during movement of the conveyance over the tripping mechanism to release the door for opening, and

contact means fixed relative to the latch release means and located at substantially the same elevation as said latch release means and in the same upright longitudinal plane therewith when said latch release means is in latch engaging position to engage successively the same longitu-- dinal portions of the conveyance, and said con tact means being in position for engagement by the under-surface of the conveyance during movement thereof over the tripping mechanismfor controlling the releasing position of the latch release means. I

The tripping face and contact face 3. In conveying mechanism, the combination with a trackway', a dumping conveyance movable along the trackway and including a' lading body with a drop bottom door, and latch means for holding the door closed and movable to release the door for opening, said latch means including engaging means for operating the latch means, of tripping mechanism mounted at the trackway and including latch release means in position to engage said engaging means during movement of the conveyance over the tripping mechanism to release thedoor for opening, and contact means fixed relative to the latch releasem'e'ans and located at substantially the same elevation as said latch release means and in the same upright longitudinal plane therewith when said latch release means is in latch engaging position, and said contact means being in position for engagement by the undersurface of the conveyance during movement thereof over the tripping mechanism for controlling the releasing position of the latch release means, and a tripping arm pivotally mounted in the trackway and supporting the latch release means and the contact means on the upper end thereof, and means yieldably urging the tripping arm upwardly to latch engaging position.

l. In conveying mechanism, the combination with a trackway, a dumping conveyance movable along the trackway and including a lading body with a drop bottom door, and latch means for holding the door closed and movable to release the door for opening, said latch means including engaging means for operating the latch means, of tripping mechanism mounted at the trackway and including latch release means in position to engage said engaging means during movement of the conveyance over the tripping mechanism to release the door for opening, and contact means fixed relative to the latch release means and located at substantially the same elevation as said latch release means and in the same upright longitudinal plane therewith when said latch release means is in latch engaging position, and said contact means being in position for engagement by the undersurface of the conveyance during movement thereof over the tripping 1nechanism for controlling the releasing position of the latch release means, and an arm plvotally mounted in the trackway for upward swinging movement relative thereto, said latch release means and contact means comprising abutments fixed on the upper end portion of the arm and spaced longitudinally thereof in positions for engagement respectively with the engaging means of the latch means and with the under-surface of the conveyance.

5. In conveying mechanism, the combination with a traclrway, a dumping conveyance movable along the trackway and including a lading body with a drop bottom door, and latch means for holding the door closed and movable to release the door for opening, said latch means including engaging means for operating the latch means, of tripping mechanism mounted at the trackway and including latch release means in position to engage said engaging means during movement of the conveyance over the tripping mechanism to release the door for opening, and contact means fixed relative to the latch release means and located at substantially the same elevation as said latch release means and in the same upright longitudinal plane therewith when said latch release means is in latch engaging position, and said contact means being in position for ftso engagement by the under-surface of the conveyance during movement thereof over the tripping mechanismhfor controlling the releasing position'of the latch release means, an arm pivotally'mounted in'thetrackway for upward swinging movement relative thereto, said latchrelease means and contact means comprising abutments fixed on theupper' end portion of the arm and spaced longitudinally thereof in positions for eng'agement respectively: with the engaging means ofthe latch means and with the under-surface of the conveyance, and means connected with the arm'and. 'yielda bly urging said arm in an upward direction.

Latch tripping mechanism adaptedtobe mounted in a track way for releasing latch means of a drop bottom door on a conveyance, said tripping mechanism comprising a tripping arm adapted to be pivotally mounted for upward swinging movement, and latch release meansand contact means mounted on the upper end portion of said tripping arm injthe same upright longitudinal lane j Q 1 V 'l. Latch tripping mechanism adapted to be mounted in a trackway for releasing latch means of a drop bottom door on a conveyance, said tripping mechanism comprising a tripping arm adapted to be pivotally mounted for upward swinging movement, and latch release means and contact means mounted on the upper end portion of said tripping arm in the same upright longhtudinal plane, said latch release means and com tact means being spaced apart longitudinally o? the tripping arm.

8. Latch tipping mechanism adapted to be mounted in a trackway for releasing latch means of a drop bottom door on a conveyance, said trip= ping mechanism comprising a tripping arm adapted to be pivotally mounted for upward swinging movement, and latch release means and contact means mounted on the upper end portion of said tripping arm in the same upright longitudinal plane, said latch release means and contact means comprising abutments spaced apart longitudinally and substantially at the same elevation in position for engagement respectively with the latch means and the under-surface of the conveyance.

9. In conveying mechanism, the combination with a trackway, a dumping conveyance movable along the trackway and including a lading body with a drop bottom door, latch means for holding the door closed and movable to release the door for opening, said latch means including engaging means for operating the latch means, of tripping mechanism mounted at the trackway including an upwardly extending arm normally inclined relative to the trackway and extending lengthwise thereof, means pivotally mounting said arm at the trackway at the rearward end portion thereof relative to the direction of movement of the conveyance along the trackway, and abutments fixed on the upper end portion of the arm and spaced longitudinally of the direction of movement of the conveyance .for engagement respectively with the latch engaging means and with the under surface of the conveyance to cause releasing movement of the latch means and to deflect the arm under the lower portion of the conveyance.

10. In conveying mechanism, the combination with a trackway, a dumping conveyance movable along the trackway and including a lading body with a drop bottom door, latch means for holding the door closed and movable to release the door for opening, said latch means including engaging means for operating the latch means, of tripping mechanism mounted at the trackway including an upwardly extending arm normally inclined relative to the trackway and extending lengthwise thereof, means pivotally mounting said arm at the trackway at the rearward end portion thereof relative to the direction of movement of the conveyance along the trackway, abutments fixed on the upper end portion of the arm and spaced longitudinally of the direction of movement of the conveyance for engagement respectively with the latch engaging means and with the under-surface of the conveyance to cause releasing movement of the latch means and to deflect the arm under the lower portion of the conveyance, said abutments being located substantially at the same elevation in the raised position of the arm, and means, for yieldably urging the arm in an upward direction.

11. Latch tripping mechanism adapted to be mounted in a trackway for releasing latch means of a drop bottom door on a conveyance, said trip- 12 ping mechanism comprising a tripping arm adapted to be pivotally mounted for upward swinging movement, and latch release means and contact means mounted on the upper end portion of said tripping arm in the same upright longitudinal plane, said latch release means and contact means comprising abutments spaced apart longitudinally and substantially at the same elevation in positions for engagement respectively with the latch means and the undersurface of the conveyance, said latch release means being located forwardly of the contact means on the arm and comprising a substantially hook shaped portion on said arm.

HUGH W. SANFORD.

REFERENCES CITED UNITED STATES PATENTS Name Date Kepner Nov. 8, 1949 Number 

